void main(){
//2.while 循环
print('-----2. while 循环-----');
int i=0;
while(i<10){
print(i);//0123456789
i++;
}


//3.do while 循环
print('-----3. do while 循环-----');
int k=0;
do{
print(k);//0 1 2 3 4 5 6 7 8 9
k++;
}while (k< 10);

}